rtc: Enable compile testing for Maxim and Samsung drivers

max8907, max77686 and s5m RTC drivers can be compile tested to increase
build coverage.  The s5m-rtc uses REGMAP_IRQ so add this as explicit
dependency.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

drivers/rtc/Kconfig

@@ -303,7 +303,7 @@ config RTC_DRV_MAX6900
 
 config RTC_DRV_MAX8907
 	tristate "Maxim MAX8907"
-	depends on MFD_MAX8907
+	depends on MFD_MAX8907 || COMPILE_TEST
 	help
 	  If you say yes here you will get support for the
 	  RTC of Maxim MAX8907 PMIC.
@@ -343,7 +343,7 @@ config RTC_DRV_MAX8997
 
 config RTC_DRV_MAX77686
 	tristate "Maxim MAX77686"
-	depends on MFD_MAX77686 || MFD_MAX77620
+	depends on MFD_MAX77686 || MFD_MAX77620 || COMPILE_TEST
 	help
 	  If you say yes here you will get support for the
 	  RTC of Maxim MAX77686/MAX77620/MAX77802 PMIC.
@@ -602,7 +602,8 @@ config RTC_DRV_RV8803
 
 config RTC_DRV_S5M
 	tristate "Samsung S2M/S5M series"
-	depends on MFD_SEC_CORE
+	depends on MFD_SEC_CORE || COMPILE_TEST
+	select REGMAP_IRQ
 	help
 	  If you say yes here you will get support for the
 	  RTC of Samsung S2MPS14 and S5M PMIC series.